U.S. patent application number 12/278506 was filed with the patent office on 2009-01-08 for spring seat of suspension.
This patent application is currently assigned to NISSAN MOTOR CO., LTD.. Invention is credited to Hitoshi Kyogoku, Hiroshi Yamakawa.
Application Number | 20090008846 12/278506 |
Document ID | / |
Family ID | 38344985 |
Filed Date | 2009-01-08 |
United States Patent
Application |
20090008846 |
Kind Code |
A1 |
Yamakawa; Hiroshi ; et
al. |
January 8, 2009 |
Spring Seat of Suspension
Abstract
A spring seat for a suspension arranged between a vehicle body
side member and a wheel side member, the spring seat supporting an
end portion of a coil spring of the suspension, wherein rigidity of
the spring seat in the orthogonal-to-axis direction of the coil
spring is smaller than rigidity of the spring seat in the axial
direction of the coil spring.
Inventors: |
Yamakawa; Hiroshi;
(Kanagawa, JP) ; Kyogoku; Hitoshi; (Kanagawa,
JP) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
NISSAN MOTOR CO., LTD.
|
Family ID: |
38344985 |
Appl. No.: |
12/278506 |
Filed: |
December 22, 2006 |
PCT Filed: |
December 22, 2006 |
PCT NO: |
PCT/JP2006/325590 |
371 Date: |
August 6, 2008 |
Current U.S.
Class: |
267/170 |
Current CPC
Class: |
B60G 2200/141 20130101;
B60G 2206/0114 20130101; B60G 2202/12 20130101; F16F 1/126
20130101; B60G 2204/4104 20130101; B60G 11/52 20130101; B60G
2204/124 20130101; B60G 3/22 20130101; B60G 11/16 20130101; B60G
2200/1442 20130101; B60G 2206/11 20130101; B60G 3/202 20130101;
B60G 2204/1244 20130101 |
Class at
Publication: |
267/170 |
International
Class: |
F16F 1/12 20060101
F16F001/12 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 8, 2006 |
JP |
2006-031158 |
Claims
1. A spring seat for a suspension arranged between a vehicle body
side member and a wheel side member, the spring seat supporting an
end portion of a coil spring of the suspension, wherein rigidity of
the spring seat in an orthogonal-to-axis direction of the coil
spring is smaller than rigidity of the spring seat in an axial
direction of the coil spring.
2. The spring seat for the suspension according to claim 1, wherein
directions in which the rigidity of the spring seat in the
orthogonal-to-axis direction of the coil spring is smaller than the
rigidity of the spring seat in the axial direction of the coil
spring are within a particular range when the spring seat is viewed
in the axial direction of the coil spring.
3. The spring seat for the suspension according to claim 2, wherein
the particular range includes a front-rear direction of a
vehicle.
4. The spring seat for the suspension according to claim 1,
comprising: a main body part for supporting an end part of an end
portion of the coil spring in the axial direction of the coil
spring; and a circumference supporting part for supporting at least
one of inner and outer circumferences of the end portion of the
coil spring, wherein, in a range of directions in which the
rigidity of the spring seat in the orthogonal-to-axis direction of
the coil spring is smaller than the rigidity of the spring seat in
the axial direction of the coil spring when the spring seat is
viewed in the axial direction of the coil spring, the circumference
supporting part is formed to have the rigidity in the
orthogonal-to-axis direction of the coil spring smaller than the
rigidity in the axial direction of the coil spring.
5. The spring seat for the suspension according to claim 4, wherein
a space part is provided to the circumference supporting part.
6. The spring seat for the suspension according to claim 4, wherein
a surface of the circumference supporting part which supports any
one of the inner and outer circumferences of the end portion of the
coil spring includes concaves and convexes.
7. The spring seat for the suspension according to claim 5, wherein
the circumference supporting part includes a slit which extends in
the orthogonal-to-axis direction of the coil spring to have the
space part communicated with an outside of the spring seat.
8. The spring seat for the suspension according to claim 5, wherein
the space part is a through hole which penetrates the circumference
supporting part in the axial direction of the coil spring.
9. The spring seat for the suspension according to claim 5, wherein
the space part is a through hole which penetrates the circumference
supporting part in the orthogonal-to-axis direction of the coil
spring.
10. Seat means for a suspension arranged between a vehicle body
side member and a wheel side member, the seat means supporting an
end portion of spring means of the suspension, wherein rigidity of
the seat means in an orthogonal-to-axis direction of the spring
means is smaller than rigidity of the seat means in an axial
direction of the spring means.
Description
TECHNICAL FIELD
[0001] The present invention relates to a spring seat for
suspension, which is used for an automobile and the like.
BACKGROUND ART
[0002] Japanese Patent Application Publication No. 2002-114015
discloses a technique which gives a directional variation in
rigidity to a bush provided between an axle member (or a wheel
carrier) connected to wheels and a suspension link member for
supporting the axle member in the vehicle body side member by
providing arc-shaped holes (spaces) to the inside of the bush. This
technique makes it possible: to maintain a change in tire position
appropriately when a load is inputted to the contact point of the
tire on a road in the front-rear direction or width direction of
the vehicle while the vehicle is turned or is running over a
protrusion on the road; and thus to enhance the driving performance
and stability.
DISCLOSURE OF THE INVENTION
[0003] Even employment of the technique, however, brings the
following problem to a suspension system which includes coil
springs each extending in the upward-downward direction of the
vehicle. Specifically, in the suspension system, an end of each
coil spring is connected to the vehicle body side member whereas
the other end of the coil spring is connected to the axle member or
the suspension link member. In addition, seat-shaped elastic
members (hereinafter referred to as a "spring seat") are interposed
between the coil spring and the vehicle body side member, and
between the coil spring and the axle member or the suspension link
member. Rigidity of each spring seat, that is, the rigidity in a
direction orthogonal to an axis of the coil spring acts as large
resistance against the change in tire position. For this reason,
even though the foregoing technique is employed, it is still
difficult to enhance the driving performance and stability by
obtaining characteristics exactly as designed.
[0004] The present invention has been made with the foregoing
problem taken into consideration. An object of the present
invention is to restrain the adjustment of the tire position from
being adversely affected by the rigidity of the spring seat, more
specifically, the rigidity in a direction orthogonal to the axis of
the coil spring.
[0005] An aspect of the present invention is a spring seat for a
suspension arranged between a vehicle body side member and a wheel
side member, the spring seat supporting an end portion of a coil
spring of the suspension, wherein rigidity of the spring seat in a
direction orthogonal to the axis of the coil spring is smaller than
rigidity of the spring seat in a direction of the axis of the coil
spring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view showing a suspension link
according to an embodiment of the present invention.
[0007] FIG. 2 is a plan view showing a spring seat according to the
embodiment of the present invention, which is attached to a
trailing arm.
[0008] FIG. 3A is a bottom plan view of the spring seat according
to the first embodiment of the present invention.
[0009] FIG. 3B is a cross-sectional view of the spring seat
according to the first embodiment of the present invention, taken
along the IIIB-IIIB line of FIG. 3A.
[0010] FIG. 4 is a diagram showing how the condition of the
trailing arm changes when a rearward load (or a rearward force) in
the front-rear direction of the vehicle is inputted to the trailing
arm from the contact point of the tire.
[0011] FIG. 5 is a graph showing a relationship between the
rearward load (or the rearward force) in the front-rear direction
of the vehicle, which is inputted to the contact point of the tire,
and a toe angle.
[0012] FIG. 6A is a bottom plan view of a spring seat according to
a second embodiment of the present invention.
[0013] FIG. 6B is a cross-sectional view of the spring seat
according to the second embodiment of the present invention, taken
along the VIB-VIB line of FIG. 6A.
[0014] FIG. 7A is a bottom plan view of a spring seat according to
a third embodiment of the present invention.
[0015] FIG. 7B is a cross-sectional view of the spring seat
according to the third embodiment of the present invention, taken
along the IIIB-IIIB line of FIG. 7A.
[0016] FIG. 8A is a bottom plan view of a spring seat according to
a fourth embodiment of the present invention.
[0017] FIG. 8B is a cross-sectional view of the spring seat
according to the fourth embodiment of the present invention, taken
along the VIIIB-VIIIB line of FIG. 8A.
[0018] FIG. 9A is a bottom plan view of a spring seat according to
a fifth embodiment of the present invention.
[0019] FIG. 9B is a cross-sectional view of the spring seat
according to the fifth embodiment of the present invention, taken
along the IXB-IXB line of FIG. 9A.
[0020] FIG. 9C is a cross-sectional view of the spring seat
according to the fifth embodiment of the present invention, taken
along the IXC-IXC line of FIG. 9A.
[0021] FIG. 10A is a bottom plan view of a spring seat according to
a 6th embodiment of the present invention.
[0022] FIG. 10B is a cross-sectional view of the spring seat
according to the 6th embodiment of the present invention, taken
along the XB-XB line of FIG. 10A.
[0023] FIG. 10C is a cross-sectional view of the spring seat
according to the 6th embodiment of the present invention, taken
along the XC-XC line of FIG. 10A.
[0024] FIG. 11A is a bottom plan view of a spring seat according to
a 7th embodiment of the present invention.
[0025] FIG. 11B is a cross-sectional view of the spring seat
according to the 7th embodiment of the present invention, taken
along the XIB-XIB line of FIG. 11A.
[0026] FIG. 11C is a cross-sectional view of the spring seat
according to the 7th embodiment of the present invention, taken
along the XIC-XIC line of FIG. 11A.
[0027] FIG. 12A is a bottom plan view of a spring seat according to
an 8th embodiment of the present invention.
[0028] FIG. 12B is a cross-sectional view of the spring seat
according to the 8th embodiment of the present invention, taken
along the XIIB-XIIB line of FIG. 12A.
[0029] FIG. 13A is a bottom plan view of a spring seat according to
a 9th embodiment of the present invention.
[0030] FIG. 13B is a cross-sectional view of the spring seat
according to the 9th embodiment of the present invention, taken
along the XIIIB-XIIIB line of FIG. 13A.
BEST MODE FOR CARRYING OUT THE INVENTION
[0031] Detailed descriptions will be provided hereinbelow for the
preferred embodiments of the present invention by referring to the
drawings.
First Embodiment
[0032] FIG. 1 is a perspective view showing a suspension link SL
according to an embodiment of the present invention.
[0033] In the suspension link SL, as shown in FIG. 1, a suspension
member 1 is arranged in the width direction of the vehicle.
Trailing arms (or suspension arms) 2 each extending in the
front-rear direction of the vehicle are arranged in the light and
left end portions of the suspension member 1, respectively. Shock
absorbers 3 are attached to the rear portion of each trailing arm 2
in the front-rear direction of the vehicle. Coil springs 4 are
attached to the middle portion of each trailing arm 2 in the
front-rear direction of the vehicle, which extend in top-bottom
direction of the vehicle. Trailing arm bushes 5 are attached to the
front portion of each trailing arm 2 in the front-rear direction of
the vehicle.
[0034] The bottom ends of the coil springs 4 are attached to the
tops of spring seats 10 provided to the trailing arms 2,
respectively. In addition, other spring seats 10 are attached to
parts of the vehicle body side member V, and thus the top ends of
the coil springs 4 are attached to this additional spring seats 10.
In other words, the top and bottom ends of the coil springs 4 are
supported by the spring seats 10 provided on the trailing arms 2
and the spring seats 10 provided on the vehicle body side member V,
respectively.
[0035] FIG. 2 is one spring seat 10 attached to its corresponding
trailing arm 2.
[0036] As shown in FIG. 2, a cylindrical fitting convex part 2a
which juts out upward (almost in parallel to a direction in which
the center axis of the coil spring 4 extends) from the top surface
of the trailing arm 2 is formed on the top surface in the middle
portion of the trailing arm 2 in the front-rear direction of the
vehicle. The spring seat 10, which is annular, is fitted to this
fitting convex part 2a. The bottom end of the coil spring 4 is
placed on the seat surface 10a of this spring seat 10.
[0037] FIGS. 3A and 3B each show one spring seat 10 according to
the first embodiment of the present invention. These drawings show,
as a representative example, one spring seat 10 which is provided
to the vehicle body side member V, and which supports the top end
of its corresponding coil spring 4.
[0038] As shown in FIG. 3, the spring seat 10 is configured of: a
main body part 11, which is almost shaped like a disc, and in whose
center portion a through-hole having a cylindrical inner
circumferential surface 11a is provided; and a protrusion part 12
which is formed in integration with the main body part 11, which
juts out downward from the circumferential portion of the
through-hole on the bottom surface of the main body part 11, and
which has a cylindrical inner circumferential surface 12b in its
center portion. The spring seat 10 is formed of an appropriate
rubber elastic body, for example, natural rubber or the like.
[0039] The bottom surface of the main body part 11 in the spring
seat 10 (or the seat surface 10a) abuts on a part of the coil
spring 4 in the axial direction, or a top end part 4c thereof.
Additionally, an outer circumferential surface 12a of the
protrusion part 12 in the spring seat 10 abuts on a top end inner
circumferential part 4a of the coil spring 4. The thickness B1 of
the protrusion part 12 in the radial direction of the coil spring 4
(or a direction orthogonal to the center axis of the coil spring 4,
and indicated by reference symbol "r" in the drawing, hereinafter
simply referred to as a "orthogonal-to-axis direction") is smaller
than the thickness B2 of the main body part 11 in the center axis
direction of the coil spring 4 (or a direction indicated by
reference symbol "y" in the drawing, hereinafter simply referred to
as an "axial direction").
[0040] The inner circumferential surface 11a of the main body part
11 and the inner circumferential surface 12a of the protrusion part
12 constitute a fitting hole 15 having a seamless cylindrical inner
circumferential surface. FIG. 2 shows how the fitting convex part
2a of the trailing arm 2 is fitted in the fitting hole 15.
[0041] Hereafter, descriptions will be provided for the
operation/working-effect of the spring seat 10 in the suspension
link SL.
[0042] In this suspension link SL, the two end portions of each
coil spring 4 in the axial direction are supported by (or held
between) spring seats 10. In each spring seat 10, specifically, the
thickness of the protrusion part 12 in the orthogonal-to-axis
direction of the coil spring 4 is smaller than the thickness of the
main body part 11 in the axial direction of the coil spring 4. This
makes the rigidity Gr of the spring seat 10 in the
orthogonal-to-axis direction of the coil spring 4 (hereinafter
simply referred to as the "rigidity Gr in the orthogonal-to-axis
direction") smaller than the rigidity Gy of the spring seat 10 in
the axial direction of the coil spring 4 (hereinafter simply
referred to as the "rigidity Gy in the axial direction")
(Gr<Gy). The rigidity Gr is a value representing how the spring
seat 10 is hard to deform when a predetermined external force is
applied to the spring seat 10 in the orthogonal-to-axis direction
of the coil spring 4, i.e., in a shear direction of the spring seat
10. This value is, for example, a value obtained by multiplying the
inverse number of the amount of deformation caused at this time by
a particular value. The rigidity Gy is a value representing how the
spring seat 10 is hard to deform when a predetermined external
force is applied to the spring seat 10 in the axial direction of
the coil spring 4. This value is, for example, a value obtained by
multiplying the inverse number of the amount of deformation caused
at this time by a particular value.
[0043] Because the rigidity of the spring seat 10 in its shear
direction (or in the orthogonal-to-axis direction of the coil
spring 4) is designed to be smaller as described above, the spring
seat 10 makes it possible to restrain the rigidity of the spring
seat 10 from adversely affecting the adjustment of the tire
position, and accordingly to enhance the controllability and
stability of the vehicle with the designed characteristic of the
tire being fully exhibited.
[0044] The spring seat 10 is capable of bringing about the
above-described effect through the simple configuration in which
the thickness B1 of the protrusion part 12 in the
orthogonal-to-axis direction of the coil spring 4 is designed to be
smaller than the thickness B2 of the main body part 11 in the axial
direction of the coil spring 4.
[0045] FIG. 4 shows how the condition of the trailing arm 2 changes
when a rearward load (or a rearward drawing: a rearward force F) in
the front-rear direction of the vehicle is inputted to the trailing
arm 2 from the contact point of the tire. In the drawing, the fine
lines indicate a condition of the trailing arm 2 before the
rearward force F is inputted to the trailing arm 2, whereas the
bold lines indicate a condition of the trailing arm 2 after the
rearward force F is inputted to the trailing arm 2.
[0046] When designing the suspension link SL, the change which
occurs in the position of the tire when a load is inputted to the
contact point of the tire in the front-rear direction of the
vehicle or on the width direction of the vehicle is adjusted by
doing things such as using the difference between the rigidity of
the arm bush 5 in the axial direction and the rigidity of the arm
bush 5 in the orthogonal-to-axis direction. In the case where, for
example, the rearward force F is inputted to the contact point of
the tire, a front end part 2b of the trailing arm 2 is sometimes
set up to provide displacement further inward in the width
direction of the vehicle (in a direction indicated by an arrow C in
the drawing). Thereby, an axle part (or a hub part) 2c is turned,
and a toe angle (or a toe-in angle) is accordingly displaced to the
side where the vehicle behavior stabilizes (as shown by an arrow D
in the drawing).
[0047] In this case, however, the coil spring 4 which is interposed
between the vehicle body side member V and the trailing arm 2, and
which connects the two components to each other, as well as the
spring seat 10 which holds the coil spring constitutes a series
spring which applies a biasing force to the trailing arm 2 in the
shear direction of the spring seat 10 (or the orthogonal-to-axis
direction of the coil spring 4), that is, in a substantially
horizontal direction. As shown by reference symbol E in the
drawing, the biasing force works as a reaction force which pushes
back the displaced front end part 2b of the trailing arm 2 both
frontward and outward in the width direction of the vehicle. This
reaction force hinders the toe angle from being displaced to the
side where the toe angle can stabilize the vehicle's behavior.
[0048] Even in this case, because the rigidity of the spring seat
10 in its shear direction (or in the orthogonal-to-axis direction
of the coil spring 4) is small, this small rigidity reduces the
reaction force which pushes back the trailing arm 2, and thus
allowing the toe angle of the axle part 2c to be displaced to the
side where the tow angle can stabilize the vehicle's behavior in
accordance with the design.
[0049] FIG. 5 is a graph showing a relationship between the
rearward load (or the rearward force F) in the front-rear direction
of the vehicle, which is inputted to the contact point of the tire,
and the toe angle (or the toe-in angle). The solid line indicates
an example employing the suspension link according to the
embodiment of the present invention. The broken line indicates an
example employing a suspension link using a suspension seat in
which the rigidity Gr in the orthogonal-to-axis direction is larger
than the rigidity Gy in the axial direction (hereinafter referred
to as a "comparative example).
[0050] In the present embodiment, the rigidity of the spring seat
10 in its shear direction (or in the orthogonal-to-axis direction
of the coil spring 4) is designed to be smaller. For this reason,
as shown in FIG. 5, a larger toe angle can be obtained relative to
the predetermined strength of the rearward force F compared to the
comparative example. In other words, the present invention enables
the toe angle of the axle part 2c to be displaced to the side where
the toe angle can stabilize the vehicle's behavior in accordance
with the design.
[0051] Descriptions will be provided hereinbelow for the other
embodiments of the present invention. Components which are the same
as those in the first embodiment will be denoted by the same
reference numerals, and descriptions for those components will be
omitted.
Second Embodiment
[0052] FIGS. 6A and 6B each shows a spring seat 210 according a
second embodiment.
[0053] As shown in FIGS. 6A and 6B, a space part 21 is made inside
the spring seat 210. The space part 21 includes: a space part 21a,
formed inside the main body part 11, which extends inward in the
radial direction from the outer peripheral end of the main body
part 11; and a space part 21b, formed inside the protrusion part
12, which extends in the axial direction, and which communicates
with the space part 21a. The space part 21a is open outward of the
spring seat 210 in its outside end in the radial direction thereof,
and thus plays a role as a slit to have the space 21b communicated
with the outside of the spring seat 210. It does not matter whether
or not the space parts 21a and 21b continue in the circumferential
direction of the spring seat 210, as long as the space parts 21a
and 21b communicate with the outside. In addition, various
cross-sectional shapes can be adopted for the space part 21
depending on purposes such as the purpose of making the rigidity of
a part of the spring seat 210 locally different from the rigidity
of the rest of the spring seat 210, and the purpose of preventing
stress concentration in a particular part of the spring seat 210.
The spring seat 210 having such a shape makes it possible to make
the rigidity Gr in the orthogonal-to-axis direction smaller than
the rigidity Gy in the axial direction, as well. As a result, the
spring seat 210 is capable of realizing the same effect as the
spring seat according to the foregoing embodiment through the
simple configuration.
Third Embodiment
[0054] FIGS. 7A and 7B show a spring seat 310 according to the
third embodiment.
[0055] As shown in FIGS. 7A and 7B, the spring seat 310 includes a
protrusion part 31 which is formed in integration with the main
body part 11, which juts out downward from the circumferential
portion of the through-hole on the bottom surface of the main body
part 11, and which has a cylindrical inner circumferential surface
32a in the center of the protrusion part 31. The protrusion part 31
is constructed in a double-wall structure which includes an inner
circumferential wall 32 and an outer circumferential wall 33. An
annular space part 34, which is open downward, is formed inside the
protrusion part 31, or between the inner circumferential wall 32
and the outer circumferential 33. In this case, the inner
circumferential surface 32a of the inner circumferential wall 32
along with the inner circumferential surface 11a of the main body
part 11 constitutes the fitting hole 15 into which the fitting
convex part 2a of the trailing arm 2 is fitted. An outer
circumferential surface 33a of the outer circumferential wall 33
abuts on the end portion inner circumferential part 4a of the coil
spring 4. Various cross-sectional shapes can be adopted for the
space part 34, like the space part 21 according to the second
embodiment. The spring seat 310 having such a shape makes it
possible to make the rigidity Gr in the orthogonal-to-axis
direction smaller than the rigidity Gy in the axial direction, as
well. As a result, the spring seat 310 is capable of realizing the
same effect as the spring seats according to the foregoing
embodiments through the simple configuration.
Fourth Embodiment
[0056] FIGS. 8A and 8B each show a spring seat 410 according to the
fourth embodiment.
[0057] As shown in FIGS. 8A and 8B, the spring seat 410 includes a
protrusion part (circumferential wall) 41 which is formed in
integration with the main body part 11, and which juts out downward
from the circumferential portion of the through-hole on the bottom
surface of the main body part 11. At least an outer circumferential
surface 41a of this protrusion part 41 abuts on the end portion
inner circumferential part 4a of the coil spring 4. An inner
circumferential surface 41b of the protrusion part 41 is located
outward, in the radial direction, of the inner circumferential
surface 11a of the through-hole in the main body part 11. As a
result, only the inner circumferential surface 11a of the
through-hole in the main body part 11 constitutes the fitting hole
15 into which the fitting convex part 2a of trailing arm 2 is
fitted. Once the fitting convex part 2a of the trailing arm 2 is
fitted in the fitting hole 15, as shown in FIG. 8B, a space 41S is
formed between the inner circumferential surface 41b of the
protrusion part 41 and the outer circumferential surface of the
fitting convex part 2a of the trailing arm 2. The thickness B3 of
the protrusion part 41 in the orthogonal-to-axis direction of the
coil spring 4 is smaller than the thickness B2 of the main body
part 11 in the axial direction of the coil spring 4. The spring
seat 410 having such a shape makes it possible to make the rigidity
Gr in the orthogonal-to-axis direction smaller than the rigidity Gy
in the axial direction, as well. As a result, the spring seat 410
is capable of realizing the same effect as the spring seats
according to the foregoing embodiments through the simple
configuration.
Fifth Embodiment
[0058] FIGS. 9A, 9B and 9C each show a spring seat 510 according to
the fifth embodiment.
[0059] As shown in FIGS. 9A, 9B and 9C, the spring seat 510
includes arc-shaped holes 51, as space parts, which penetrate the
main body part 11 and the protrusion part 21 in the axial
direction. In other words, once the spring seat 510 is fitted to
the fitting convex part 2a of the trailing arm 2, the arc-shaped
holes 51 as the space parts are located in the circumferential
portion of the fitting hole 15 of the spring seat 510, or in the
circumferential portion of the fitting convex part 2a of the
trailing arm 2. Various cross-sectional shapes can be adopted for
the arc-shaped holes 51 depending on purposes such as the purpose
of making the rigidity of a part of the spring seat locally
different from the rigidity of the rest of the spring seat, and the
purpose of preventing stress concentration in a particular part of
the spring seat. The spring seat 510 having such a shape makes it
possible to make the rigidity Gr in the orthogonal-to-axis
direction smaller than the rigidity Gy in the axial direction, as
well. As a result, the spring seat 510 is capable of realizing the
same effect as the spring seats according to the foregoing
embodiments through the simple configuration.
[0060] In addition, when the spring seat 510 is viewed in the axial
direction of the coil spring 4, the arc-shaped holes 51 are placed
in a particular angular range a about the center axis of the spring
seat 510. The placement of the arc-shaped holes 51 each subtending
the particular angle range a makes it possible to limit an
direction which makes the rigidity Gr in the orthogonal-to-axis
direction smaller than the rigidity Gy in the axial direction to a
predetermined angular range about the center axis of the spring
seat 510. For example, when the direction which makes the rigidity
Gr in the orthogonal-to-axis direction smaller than the rigidity Gr
in the axial direction is matched with the front-rear direction of
the vehicle, the spring seat 510 according to the fifth embodiment
is capable of realizing the same effect as the spring seats
according to the foregoing embodiments, and of maintaining its high
rigidity in the width direction of the vehicle, as well as
accordingly of enhancing the driving stability.
6th Embodiment
[0061] FIGS. 10A, 10B and 10C each show a spring seat 610 according
to a 6th embodiment.
[0062] In the spring seat 610, as shown in FIGS. 10A, 10B and 10C,
the protrusion part 12, which is formed in integration with the
main body part 11, and which juts out downward from the
circumferential portion of the through-hole on the bottom surface
of the main body part 11, is divided into multiple blocks 61 in its
circumferential direction. The cross-sectional shapes of the
respective blocks 61 into which the protrusion 12 is divided are
not limited to shapes shown in the drawing. Any single block 61
subtending a predetermined angular range may be further divided
into multiple blocks in the circumferential direction of the
protrusion part 12. The spring seat 610 having such a shape makes
it possible to make the rigidity Gr in the orthogonal-to-axis
direction smaller than the rigidity Gy in the axial direction, as
well. As a result, the spring seat 610 is capable of realizing the
same effect as the spring seats according to the foregoing
embodiments through the simple configuration.
7th Embodiment
[0063] FIGS. 11A, 11B and 11C each show a spring seat 710 according
to a 7th embodiment.
[0064] In the spring seat 710, as shown in FIGS. 11A, 11B and 11C,
multiple slits 71 radially extending outward from the respective
positions in the radial directions are formed in the protrusion
part 12, which is formed in integration with the main body part 11,
and which juts out downward from the circumferential portion of the
through-hole on the bottom surface of the main body part 11. The
slits 71 are arranged at equal intervals in the circumferential
direction of the protrusion part 12. The cross-sectional shapes of
the respective slits 71 are not limited to the shapes shown in the
drawing. For example, the cross-sectional shapes of the respective
slits 71 may become progressively wider toward their outer ends in
the radial direction. Otherwise, the cross-sectional shapes of the
respective slits 71 may be discontinuous in the radial direction.
The depths of the respective slits 71 in the axial direction may be
changed depending on the necessity. The depth and cross-sectional
shape of each of the slits 71 may be changed depending on where the
slit 71 is located in the circumferential direction. The spring
seat 710 having such a shape makes it possible to make the rigidity
Gr in the orthogonal-to-axis direction smaller than the rigidity Gy
in the axial direction, as well. As a result, the spring seat 710
is capable of realizing the same effect as the spring seats
according to the foregoing embodiments through the simple
configuration.
8th Embodiment
[0065] FIGS. 12A and 12B each show a spring seat 810 according to
an 8th embodiment.
[0066] In the spring seat 810, as shown in FIGS. 12A and 12B,
multiple bored holes 81 are formed in the protrusion part 12 which
is formed in integration with the main body part 11, and which juts
out downward from the peripheral portion of the through-hole on the
bottom surface of the main body part 11, in a way that the bored
holes 81 penetrate the protrusion part 12 in the radial direction
of the spring seat 810. The bored holes 81 are formed in each of
partial areas .beta., as indicated by dotted diagonal lines in FIG.
12A, in the protrusion part 12 in its circumferential direction.
For example, as shown in FIG. 12B, the multiple bored holes 81 are
formed and arrayed in the axial direction of the protrusion part
12. These bored holes 81 may or may not be formed in parallel to
each other. The cross-sectional shape of each bored holes 81 may be
circular, or may be polygonal. In addition, the diameter of each
bored hole 81 may become progressively larger toward the outer end
in the radial direction of the spring seat 810, or may become
progressively smaller toward the outer end of the radial direction
thereof. The spring seat 810 having such a shape makes it possible
to make the rigidity Gr in the orthogonal-to-axis direction smaller
than the rigidity Gy in the axial direction, as well. As a result,
the spring seat 810 is capable of realizing the same effect as the
spring seats according to the foregoing embodiments through the
simple configuration.
[0067] It should be noted that, in the spring seats 610, 710 and
810 shown in FIGS. 10A to 12B, the concaves and convexes are formed
on the side surface 12a of the protrusion part 12 supporting the
end portion inner circumferential part 4a of the coil spring 4.
Specifically, the spaces between each two neighboring blocks 61 in
the spring seat 610, the slits 71 in the spring seats 710, and the
bored holes 81 in the spring seat 810 each constitutes a concave,
which is hollowed inward in the radial direction, on the side
surface 12a of the protrusion part 12. On the other hand, the
portions of the side surface 12a of the protrusion part 12, which
abut on the end portion inner circumferential part 4a of the coil
spring 4, that is, portions other than the abovementioned spaces
between each two neighboring blocks 61, the slits 71, and the bored
holes 81, each constitutes a convex, which juts out in the radial
direction, on the side surface 12a of the protrusion part 12.
[0068] In the case where, as described above, the concaves and
convexes are formed on the side surface of the protrusion part 12
which supports the end portion inner circumferential part 4a of the
coils spring 4, it is possible to make the rigidity of the
protrusion part 12 in the shear direction (or in the
orthogonal-to-axis direction) smaller than the rigidity of the
protrusion part 12 in a compressing direction (or in the axial
direction). This is because, when an external force is applied to
the spring seat in its shear direction, the load concentrates on
the convex parts abutting on the end portion inner circumferential
part 4a of the coil spring 4, and the convex parts are accordingly
easy to deform elastically. In addition, while the spring seat is
being fitted to the coil spring 4, it is possible to make the
aggregate rigidity of the spring seat and the coil spring 4 in the
orthogonal-to-axis direction smaller than the aggregate rigidity
thereof in the axial direction because the shear direction of the
protrusion part 12 conforms to the direction of the
orthogonal-to-axis direction of the coil spring 4, and the
compressing direction of the protrusion part 12 conforms to the
direction of the axial direction of the coil spring 4.
9th Embodiment
[0069] FIGS. 13A and 13B each show a spring seat 910 according to a
9th embodiment.
[0070] As shown in FIGS. 13A and 13B, the spring seat 910 includes
a protrusion part 910 which is formed in integration with the main
body part 11, and which juts out downward from the outer
circumferential portion on the bottom surface of the main body part
11, which also has a cylindrical inner circumferential surface 91a
in its inside in the radial direction of the spring seat 910. As
the structure for making the rigidity Gr in the orthogonal-to-axis
direction smaller that the rigidity Gy in the axial direction, for
example, a space part 92 similar to the space part according to the
first embodiment may be provided inside the spring seat 910. In
this respect, the space part 92 is configured of: a space part 92a
which is formed inside the main body part 11, and which extends
outward in the radial direction of the spring seat 910 from an
inner peripheral end portion of the main body part 11; and a space
part 92b which is formed inside the protrusion part 92, and which
extends in the axial direction, which also communicates with the
space part 92a. An inside end portion of the space part 92a in its
radial direction is open inward the spring seat 910 in its radial
direction, and thus plays a function of a slit having the space
part 92b communicated with the outside of the spring seat 910. An
end portion of the coil spring 4 is situated inside the protrusion
part 91 in its radial direction with the external side surface 4b
of the coil spring 4 in its radial direction abutting on the inner
circumferential surface 91a of the protrusion part 91. The spring
seat 910 having such a shape makes it possible to make the rigidity
Gr in the orthogonal-to-axis direction smaller than the rigidity Gy
in the axial direction, as well. As a result, the spring seat 910
is capable of realizing the same effect as the spring seats
according to the foregoing embodiments through the simple
configuration.
[0071] Furthermore, protrusion parts of the above-described type
may be respectively provided to both the inner and outer
circumferences of the end portion of the coil spring 4. In this
case, the end portion of the coil spring 4 is designed to be
supported by the protrusion parts respectively provided to the
inner and outer circumferences thereof in a way that the end
portion of the coil spring 4 is interposed between the protrusion
parts. Even in this case, the aggregate rigidity Gr of the
protrusion parts in the inner and outer circumferences thereof in
the orthogonal-to-axis direction is smaller than the rigidity Gy of
the spring seat 910 in the axial direction.
[0072] In the cases of the foregoing embodiments, the rigidity Gr
of the spring seat in the orthogonal-to-axis direction is designed
to be smaller than the rigidity Gy of the spring seat in the axial
direction by employing the various shapes of the spring seat.
However, the method of adjusting the rigidities is not limited to
the employment of the shapes in the foregoing embodiments. For the
purpose of making the rigidity Gr of the spring seat in the
orthogonal-to-axis direction smaller than the rigidity Gy of the
spring seat in the axial direction, for example, different
materials may be used to form the spring seat depending on the
locations of the respective parts in the spring seat. In addition,
it is possible to make the rigidity Gr of the spring seat in the
orthogonal-to-axis direction smaller than the rigidity Gy of the
spring seat in the axial direction, for example, by using a
material, for the protrusion part 12 of the spring seat, which is
easier to elastically change in form than a material used for
forming the main body part 11.
[0073] The spring seats, which have been shown, are based on the
premise that the fitting convex part 2a of the trailing arm 2 is
fitted into the fitting hole 15 from the main body part 11 through
the protrusion part 12. Nevertheless, the fitting convex part 2a
may be designed to be situated only inside of the main body part
11, and not inside of the protrusion part 12. Only the inside of
the inner circumferential surface 11a of the main body part 11 of
the spring seat is fitted to the fitting convex part 2a, for
example, by making the amount of protrusion of the fitting convex
part 2a smaller (or lowering the height of the fitting convex part
2a from a portion of the top surface of the trailing arm 2 which
abuts on the spring seat). The spring seat thus designed makes it
possible to make the rigidity Gr in the orthogonal-to-axis
direction smaller than the rigidity Gy in the axial direction, as
well. As a result, the spring seat thus designed is capable of
realizing the same effect as the spring seats according to the
foregoing embodiments through its simple configuration.
[0074] The foregoing embodiments have been described citing the
suspension link SL in which, as shown in FIG. 1, the shock
absorbers 3 and the coil springs 4 are arranged in their respective
locations which are different from one to another in the horizontal
direction. Nevertheless, the type of the suspension link is not
limited to the type shown in FIG. 1. For example, a suspension link
in which the shock absorbers are inserted in the respective coil
springs may be used instead. In this case, each spring seat is
designed to be formed along the perimeter of the external cylinder
of the corresponding shock absorber. Even in this case, when the
coil spring seat is formed in any one of the forgoing shapes, it is
possible to make the rigidity Gr in the orthogonal-to-axis
direction smaller than the rigidity Gy in the axial direction, as
well. As a result, the spring seat is capable of realizing the same
effect as the spring seats according to the foregoing embodiments
through its simple configuration.
[0075] As exemplified as each of the preferred embodiments of the
present invention, the spring seat (10, 210, 310, 410, 510, 610,
710, 810 and 910) of the suspension according to the present
invention supports the end portion of the corresponding coil spring
(4) in the suspension (SL) arranged between the vehicle body side
member (V) and the wheel side member (2c), and the rigidity (Gr) of
the spring seat in the orthogonal-to-axis direction (r) of the coil
spring (4) is smaller than the rigidity (Gy) of the spring seat in
the axial direction (y) of the coil spring (4).
[0076] In the spring seat (10, 210, 310, 410, 510, 610, 710, 810
and 910), it is desirable that the direction which makes the
rigidity (Gr) of the coil spring seat (4) in the orthogonal-to-axis
direction (r) of the coil spring (4) smaller than the rigidity (Gy)
of the coil spring seat (4) in the axial direction (y) should be
within a particular range (.alpha., .beta.) when the spring seat is
viewed in the axial direction of the coil spring. Furthermore, it
is desirable that the particular range (.alpha., .beta.) should
include the front-rear direction of the vehicle.
[0077] Additionally, it is desirable that the spring seat (10, 210,
310, 410, 510, 610, 710, 810 and 910) should include: a main body
part (11) for supporting an end part (4c) of an end portion of the
coil spring (4) in the axial direction of the coil spring (4); and
a circumference supporting part (12, 31, 41, 61, 81 and 91) for
supporting at least one of the inner and outer circumferences (4a,
4b) of the end portion of the coil spring (4). Concurrently, it is
desirable that, in the direction which makes the rigidity (Gr) of
the spring seat (10, 210, 310, 410, 510, 610, 710, 810 and 910) in
the orthogonal-to-axis direction (r) of the coil spring (4) smaller
than the rigidity (Gy) of the spring seat (10, 210, 310, 410, 510,
610, 710, 810 and 910) in the axial direction (y) of the coil
spring (4) when circumference supporting part (12, 31, 41, 61, 81
and 91) is viewed in the axial direction of the coil spring (4),
the circumference supporting part (12, 31, 41, 61, 81 and 91) is
formed to have the rigidity (Gr) in the orthogonal-to-axis
direction (r) of the coil spring (4) smaller than the rigidity (Gy)
in the axial direction (y) of the coil spring (4).
[0078] Moreover, it is desirable that a space part (21, 34, 51, 71,
81 and 92) should be provided to the circumference supporting part
(12, 31, 41, 61, 81 and 91) in the spring seat (10, 210, 310, 410,
510, 610, 710, 810 and 910).
[0079] In addition, in the spring seat (10, 210, 310, 410, 510,
610, 710, 810 and 910), it is desirable that the surface (12a, 33a,
41a and 91a) of the circumference supporting part (12, 31, 41, 61,
81 and 91) which supports any one of the inner and outer
circumferences (4a and 4b) of the end portion of the coil spring
(4) includes concaves and convexes.
[0080] Additionally, in the spring seat (10, 210, 310, 410, 510,
610, 710, 810 and 910), it is desirable that the circumference
supporting part (12, 31, 41, 61, 81 and 91) includes a slit (21a,
71 and 92a) which extends in the orthogonal-to-axis direction (r)
of the coil spring (4) to have the space part (21, 34, 51, 71, 81
and 92) communicated with an outside of the spring seat.
[0081] Furthermore, in the spring seat (10, 210, 310, 410, 510,610,
710, 810 and 910), it is desirable that the space part is a
through-hole (51 and 81) which penetrates the circumference
supporting part (12, 31, 41, 61, 81 and 91) in any one of the axial
direction (y) and the orthogonal-to-axis direction (r) of the coil
spring (4).
[0082] It should be noted that the embodiments of the present
invention have been described only for the purpose of exemplifying
the present invention, and that the present invention is not
limited to the embodiments. For example, any combination of the
embodiments depending on the necessity, and a change or
modification which is applied to any one of the embodiments within
the technical scope of the present invention are all included in
the scope of the present invention. Examples of the combination of
the embodiments include: a configuration in which the slit is
provided to the protrusion part in the spring seat with the space
part being included in the protrusion part; a configuration in
which a part of the spring seat including the through-hole is
formed of a material different from that used to form the rest of
the spring seat; and a configuration in which concaves and convexes
are provided to the side surface of the protrusion part for
supporting the outer circumferential portion of the end portion of
the coil spring from outside in the radial direction of the coil
spring.
[0083] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2006-031158 filed on
Feb. 8, 2006, the entire contents of which are incorporated herein
by reference.
INDUSTRIAL APPLICABILITY
[0084] The spring seat for the suspension according to the present
invention makes it possible to restrain the adjustment of tire
position from being adversely affected by the rigidity of the
spring seat, because the rigidity of the spring seat in the
orthogonal-to-axis direction of the coil spring is designed to be
smaller than the rigidity of the spring seat in the axial direction
of the coil spring. For this reason, the spring seat for the
suspension according to the present invention is industrially
applicable.
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